Last.fm is a website on which one can create a profile and then download the free program that comes with the site in order to have it automatically chart the music you listen to, displaying it as it plays in iTunes.
http://www.last.fm/
For example, here is my profile:
http://www.last.fm/user/Twentyonejeepee
Here's my Data Realms group for you to join. We already have 14 members, let's get more.
http://www.last.fm/group/Data+Realms+Forum+Members

I hate last.fm, they give TOO much variety, I get a bowling for soup station and hear one song a day...

What do you mean?

I search for a band and I hear one song from them in an hour. And the rest of the crap is completely irrelevant to the genre.

According to Last.fm, Iron Maiden sounds just like Duran Duran.

I joined.
That's 15 members.
You people who listen to Christina Aguilara should be ashamed of yourselves.

Protip: Every song more or less has every tag. I found "Deep African Vocalist" in more or less every Iron Maiden song I have.

Deep African vocalist? For the Irons? WHAT THE F_CK?
And I'm not too into Last.FM, but des it show the music I'm listening to in WMP as well? Because theres no way on Earth you'll get me on there to listen to Duran Duran when I want Maiden.

And there's no way I'll listen to Avril Lavigne when I want Fall Out Boy (yes, that's happened before)...

I just use Last.fm as a sort of musical diary. Hm...

Why would you want to listen to Fall Out Boy, anyway? They can't even spell fallout correctly.

Because they're awesome, and the last time I checked both Fall and Out are words, they weren't trying to spell Fallout.

How are they awesome? Every Fall Out Boy song is the same.

Quit flaming, everyone has their own opinions and you have no reason to flame someone on what they like. Plus, Alenth, wizzy J, everybody almost on IRC loves Fall Out Boy.

In my opinion they're too [sexually unstable], I prefer music tat makes me wanna bang my head in the wall.